复合金属颗粒材料的非线性光学和极化率研究  

THE RESEARCH OF NONLINEAR OPTIC AND SUSCEPTIBILITIES TO COMPOSITE MAGNETIC GRANULES

作　　者：卢孟春[1] 郑勇林[1,2] 严刚峰[2] 刘鸿[2] 杨维[2] 王晓茜[2] 

机构地区：[1]长江师范学院凝聚态物理研究所,重庆408100 [2]成都大学电子信息工程学院,成都610106

出　　处：《低温物理学报》2013年第3期209-213,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:11205022);重庆市教委科学技术研究项目(批准号:KJ061305;KJ081307)资助的课题~~

摘　　要：从复合材料的电位移D和电场E之间的非线性关系出发.假设线性介电常数εi0和立方非线性极化率χi(3)的介电函数是对角线性量与非对角磁化量复合而成,由此提出了简单的有效介质近似方法用于计算磁性金属-绝缘体颗粒合金的有效介电函数.对于这种磁性金属-绝缘体复合材料的磁光效应依赖于光的强度、立方非线性χi(3),有效介质函数的值可显著的大于单一组成材料(高达103倍)的值.由Bergman和Stroud-Hui理论计算复合磁性颗粒材料的非线性光学性质发现,复合磁性颗粒材料的立方磁光非线性在磁性金属体积分数接近逾渗阈值附近将产生磁光共振,这表明:复合材料可能产生非线性的磁光效应,对单一材料没有立方非线性光学属性时也有这种效应.The article propose a simple effective-medium approach for calculating the effective dielectric function of a magnetic metal-insulator granular alloy in which there is a weakly nonlinear relation between electric displacement D and electric field E for both constituent materials. Assume the dielectric functions that dielectric constant of linear εi（0） and cubic nonlinear susceptibilities χi（3） are diagonal＇s linear with magnetization of nondiagonal components. For such magnetic metal-insulator composite magneto-optical effects depend on a light intensity, and the effective cubic dielectric function χi（3） can be significantly greater （up to 103 times） than that for constituent materials. The calculation scheme is based on the Bergman and Stroud-Hui theory of nonlinear optical properties of granular matter. It will produce the magneto-optical resonance to composite magnetic granules in magnetic metal volume fraction near the percolation threshold. It is shown that a composite may exhibit nonlinear magneto-optics even when both constituent materials have no cubic magneto-optical.

关 键 词：磁性纳米颗粒 光学非线性 磁光特性 非线性极化率 

分 类 号：O437[机械工程—光学工程]